ar-pro (2-pack) ar-pro 15x6.00-6" inner tubes with tr-13 straight valve stem - replacement lawn mower tire tubes with tr13 straight valve stem - suitable for yard tractors, wheelbarrows, atvs, and more 15x6.00-6,tr-13 is up for auction in Patio, Lawn & Garden. The current bid is $1.00, 92% below the $12.79 MSRP, in Good Condition. This auction has ended — similar items appear in live auctions regularly.