Alpinestars Youth SM3 Jettson Helmet

Size chart

Clothing Size Conversion Chart
Category	US	EU	UK	Chest (in)	Waist (in)	Hips (in)
Men	XS	44	34	32-34	26-28	33-35
	S	46	36	34-36	28-30	35-37
	M	48	38	38-40	32-34	39-41
	L	50	40	42-44	36-38	43-45
	XL	52	42	46-48	40-42	47-49
Women	XS	32	6	31-32	24-25	33-34
	S	34	8	33-34	26-27	35-36
	M	36	10	35-36	28-29	37-38
	L	38-40	12-14	37-39	30-32	39-41
	XL	42	16	40-42	33-35	42-44
Youth	XS	128	7	26-28	23-24	26-28
	S	134	8	28-30	24-25	28-30
	M	140	10	30-32	25-26	30-32
	L	146	12	32-34	26-27	32-34
	XL	152	14	34-36	27-28	34-36

Pants Size Conversion Chart
Category	US	EU	UK	Waist (in)	Hip (in)	Inseam (in)
Men	28	44	28	28	34	30
	30	46	30	30	36	31
	32	48	32	32	38	32
	34	50	34	34	40	33
	36	52	36	36	42	34
Women	0	32	4	24	34	30
	2	34	6	25	35	30
	4	36	8	26	36	31
	6	38	10	27	38	32
	8	40	12	28	40	32

Shoes Size Conversion Chart
Category	US	EU	UK	Foot Length (in)
Men	6	39	5.5	9.25
	7	40	6.5	9.625
	8	41	7.5	10
	9	42	8.5	10.25
	10	43	9.5	10.625
	11	44	10.5	11
	12	45	11.5	11.25
	13	46	12.5	11.625
Women	5	35	2.5	8.5
	6	36	3.5	8.875
	7	37	4.5	9.25
	8	38	5.5	9.625
	9	39	6.5	10
	10	40	7.5	10.25
	11	41	8.5	10.625
	12	42	9.5	11
M (Unisex)	5	37	4.5	8.75
	6	38	5.5	9
	7	39	6.5	9.5
	8	40	7.5	10
	9	41	8.5	10.25
	10	42	9.5	10.625
	11	43	10.5	11
	12	44	11.5	11.25

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Alpinestars Youth SM3 Jettson Helmet Crafted to cater to the needs of young adventurers, the SM3 Youth Helmet offers a fine-tuned balance of performance, protection, and comfort for future champions in MX, Enduro, and Off-road racing. The helmet incorporates cutting-edge technologies from Alpinestars’ adult helmet lineup, all while providing an anatomical fit tailored for youth riders. This helmet ensures the upcoming generation of racers is well-equipped to tackle any challenge on the track. Shell: Thermo-injected shell 3 shell sizes SM3 Youth weighs 1060g (ECE) and 1170g (DOT) Fit can be tailored to the rider’s head replacement liner and cheekpads DOT certified version of the helmet’s inner shell is constructed with a composite fiber assembled between the outer shell and the EPS liner for maximum protection against impacts Comfort: Youth Medium (YM) and Youth Large (YL) sizes share the same EPS size The Youth Small (YS) has a smaller EPS size and can be customized only via the cheek pads Youth Small sizes are very small, typically 3 to 4 years old, and therefore they require a dedicated helmet fit Multiple density inner liner ensures the helmet is equipped with the correct density in the correct area for enhanced impact absorption Inner and outer surfaces are engineered to minimize the effects of oblique impacts Alpinestars patented low friction coating is applied to the inner part of the main EPS liner to reduce the rotational acceleration forces 10 inlets and seven exhaust ports 25mm soft textile chin strap Safety: Stainless steel D-rings Emergency Release System and removable cheek pads DOT and ECE 22.06 certified Features: Visor directs air into ports Patented visor release system Integrated hydration tube channels in cheek pads

color

Grey/Purple/Black

Size

Youth LG

Youth MD

Youth SM