UPGRADE from 1/4" to 1/2 Valves and airlines fittings NOTE:Must use 120psi or lower psi switch

Replaces your 1/4" (4mm) standard trainhorn valve to a 1/2" 15mm valve and 1/2" airhose and fittings. Makes the horn twice as loud.. Stupid Loud!

This product is available exclusively as an upgrade with a qualified kit purchase, substituting for an upgraded item. Please ensure you have an eligible upgradeable kit before placing an order.

For assistance or questions, contact our Sales Team at 800-842-8789 Monday - Friday 8:00am - 5:00pm Arizona Time Zone.