.The OX-P025702 OX Pro Chalk Refill Blue 226g is a premium quality chalk powder formulated for clear and accurate line marking. Its fine particle consistency ensures sharp, long-lasting lines, while the bright blue colour provides excellent visibility on most surfaces, both indoors and outdoors. Supplied in a 226g easy-fill bottle, it’s ideal for quick refills of OX Trade and Pro chalk line reels. A reliable marking solution for professional tradespeople.